Great source of information on using RRDtool
I’m (once again) in an RRDtool coding time and I found this (dead?) blog, full of really nice explanations and examples on how to enlighten your RRDtool graphs. I’m actually using the information to render my Xymon metrics in a better way. Be sure to read the Circles of Archimedes for pretty stylish graphs!
Monitor Dovecot with Munin on OpenBSD
At the time of writing, Munin on OpenBSD doesn’t come with a dovecot dedicated plugin. I’m not sure it even comes with an IMAP plugin. Anyway, you can get one from the “Munin plugin repository” and run it on your BSD box. Here’s how: